Biological Cofactors
FULL PAPER
temperatures to room temperature, is unknown, as well as
any possible effects of dissolving the residues in water. As a
result, it is not possible to derive any conclusions on the ini-
tial abundance of these products in photolyzed ice mantles
in the interstellar medium. The reported species should be
searched for in environments where annealing of icy grains
took place, like hot cores or our solar system, where the ag-
glomeration of such grains might have led to the formation
of asteroids and comets. Interplanetary dust particles of as-
teroidal or cometary origin could host some of these prod-
ucts, but their small mass (of the order of nanograms) would
currently prevent their detection in individual particles.
Following the abiotic synthesis of adenine from hydrogen
cyanide,[30] other nucleic bases were produced under simulat-
ed primitive Earth conditions,[31] as well as different N- and
O-heterocycles. A large number of N-heterocyclic molecules
were found to be constituents of the Murchison meteorite,
among them biochemical compounds, such as purines and
uracil.[32] To our knowledge, there is no exact correspon-
dence between the N-heterocycles currently detected in our
samples and those found in Murchison. Nevertheless, the N-
heterocyclic compounds reported here are similar to those
which are very likely to be present in the dust of comet
Halley, that is, pyrrole, pyridine, pyrimidine, and its deriva-
tives.[9] Similar N-heterocycles were also observed in comet
81P/Wild 2.[33]
Acknowledgements
Our collaboration was originally supported by the Max-Planck-Institut
für Sonnensystemforschung (former Max-Planck-Institut für Aeronomie)
at Katlenburg-Lindau with grants for G.M.M.C. and U.J.M., as preparato-
ry work for the Rosetta mission. The work was performed at the Sackler
Laboratory for Astrophysics at Leiden Observatory and the Centre Bio-
physique MolØculaire at Orleans. U.J.M. is grateful for a research posi-
tion, GC–MS equipment, and a research group funded by the Deutsche
Forschungsgemeinschaft DFG, Bonn, Germany, and a “poste rouge” of
the CNRS at the UniversitØ de Nice–Sophia Antipolis, France. G.M.M.C.
thanks the Marie Curie Individual Fellowship Program from the Europe-
an Community for financial support.
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